Although radionuclides have been used therapeutically for several decades, the main concern has been their accumulation in non-target healthy tissues. This problem can be controlled by magnetically targeted delivery of radionuclides' nanoparticle carriers with chemotherapeutic agents. Such chemotherapeutic agent-loaded radionuclide carriers can be injected to a patient and controlled by an external magnetic field for targeted drug delivery and selective radiotherapy. Also, incorporating hazardous radionuclides in these carriers can be challenging, so the process must be amenable to large amounts of radioactivity and radionuclides with short half-lives. Neutron activation of particulates with stable isotopes as a means of producing carriers of radioactive isotopes can overcome these limitations.
Particles for the treatment of cancer in combination with x-ray radiotherapy have been reported. For example a metal oxide such as titanium dioxide, zinc oxide, cerium oxide and mixtures of two or more were doped with rare earth elements. Radioactive holmium-166-loaded poly (L)-lactic acid (PLLA) microspheres have been reported for treatment of liver malignancies. A disadvantage of holmium-loaded PLLA microspheres is the limited loading capacity of holmium. The average holmium loading in these microspheres is ˜17% (w/w). 165Ho and 164Dy containing magnetic nanoparticles with anticancer drugs can be used for magnetically targeted radiotherapy and chemotherapy at the same time. This application seeks to solve this problem by providing nanoparticles with high drug loading capacity which can provide efficient radiotherapy. In some embodiments, nanoparticles associated with radiosensitizers, as disclosed in this application, are capable of mediating toxic effects when the nanoparticles emit radiation at sub-toxic (subtherapeutic) levels.